VLogs: add support for Statefulset

[alongwill]

The Victoria Logs helm chart allows the creation of a StatefulSet:
https://github.com/VictoriaMetrics/helm-charts/blob/master/charts/victoria-logs-single/templates/server-statefulset.yaml

Can the operator please be updated to support this too?

[f41gh7]

It'd be great to know a motivation for this feature. VLogs is intended to be application with a single replica. There is no way to scale it.

Meanwhile, StatefulSet is only complicates management of resource. It's not possible to create automated migration path from Deployment to Statefulset without complete data loss.